Answer: 33
Step-by-step explanation: In the problem, you are given the figure with the following:
2x+3 and 3x+12
Method: Lets set this into an equation. Remember that straight lines add up to 180°.
2x+3+3x+12=180° Combine like terms.
5x+15=180°
5x=165°
x=33°
You can always plug in 33° in the expression that was set to make sure it does give you 180°.
Hope this helps.